JP2928875B2 - Sealing mechanism of artificial heart pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a pump used for an artificial heart used in a human body, and more particularly to a reliable shaft seal for blood of a bearing of a rotary shaft for driving a pump provided in an artificial heart body. And a seal mechanism of the artificial heart pump that can maintain

[0002]

2. Description of the Related Art In an artificial heart used in a human body which has been researched and developed in recent years, blood in the left ventricle is injected into the aorta from the tip of a nozzle penetrating an aortic valve by an axial flow pump built into the body of the artificial heart. There is a form to send to.

FIG. 10 is an explanatory view showing a state in which a conventional artificial heart main body is attached to a human heart.

[0004] An artificial heart 1 includes a tubular apex ring 2 that is implanted and fixed through an apex C of a left ventricle B of a heart A,
And the artificial heart body 3. The artificial heart main body 3 includes a cylindrical pump base 4 inserted through the apex ring 2 into the left ventricle of the heart, a casing 6 formed at the tip of the pump base, and a pump outside the human heart. And a drive unit 5 disposed to be connected to the base end of the pump base and to drive an axial pump incorporated in the casing. The nozzle 7 at the tip of the casing is the aortic valve D of the heart A.
And inserted into the ascending aorta E. At the lower end of the casing 6, a plurality of suction ports 8 for sucking blood in the left ventricle are provided, and the blood in the left ventricle is sucked into the casing 6 from the suction port 8 and the nozzle section 7 is provided. From the ascending aorta. When the above-described axial flow pump is used as a blood pump, the biggest problem is the sealing of the rotating shaft that drives the axial flow pump with respect to blood. If blood enters the sliding surface of the bearing provided on the rotating shaft of the axial flow pump, protein components such as fibrinogen contained in the blood are denatured and coagulated on the sliding surface of the bearing by the heat of rotational friction. It causes adhesion and stops the rotation of the shaft. Therefore, in order to prevent this, an oil seal is attached to the rotating shaft, and the sealed liquid bag 50 is inserted from the tip of the oil seal.
By continuously flowing the sealing liquid sealed in the oil into the blood via the flow tube 51, the penetration of blood into the oil seal was prevented.

[0005]

However, in the above-mentioned sealing method, it is necessary to consume a large amount of sealing liquid so that blood components do not enter the sliding surface between the oil seal and the rotating shaft. If the flow rate of the sealing liquid is increased, it is necessary to frequently change the sealing liquid bag for replenishment of the sealing liquid, which is not preferable because the burden on the patient increases accordingly. Furthermore, in the vicinity of the sliding surface where the oil seal and the rotating shaft are in contact, the denatured and coagulated blood protein easily adheres and grows. As a result, the grown blood protein component spreads the sliding surface of the oil seal and impairs the sealing performance. The scene was seen. Furthermore, since the shape of the flow path through which blood flows is determined by the shape of the oil seal,
It is difficult to obtain an ideal flow path shape, and blood tends to stay. Further, in the case of an oil seal using silicon rubber or the like, it is very difficult to maintain the initial performance for a long period of time.

The present invention has been made in view of such a situation, and an object of the present invention is to ensure that a shaft seal of a rotating shaft of a pump with respect to blood can be reliably maintained for a long period of time. An object of the present invention is to provide an artificial heart pump that consumes a small amount of liquid and a seal mechanism for a rotating shaft thereof.

[0007]

According to the artificial heart pump of the present invention, a driving part (5) for driving a moving blade (16) attached to a rotary shaft, and a base end and a distal end of the rotary shaft are supported. It has a bearing and has a smooth radial contact with the rotating shaft for preventing blood from entering the sliding surfaces of the bearing rotors (14a, 14b) and the bearing stator (11a) from the tip of the pump base (4). At least one set of end face rotary contact type seals (hereinafter referred to as mechanical seals) (9) having surfaces, a fluid chamber (24) formed between the mechanical seals (9) and the bearing rotor (14a); This fluid chamber (24)
And a circulating mechanism for circulating a circulating fluid for flushing the mechanical seal portion (9) facing the circulating fluid.

That is, according to the present invention, at least one set of mechanical seals of a rotating end face having a smooth contact surface is provided, and a circulating fluid for rinsing the mechanical seal portion and a circulating mechanism thereof are provided. It is characterized by.

Lubrication is maintained by forming a fluid thin film having a thickness of about 0.5 to 1.0 μm between opposed smooth contact surfaces of the mechanical seal. Since one end of the contact end face of the mechanical seal is exposed to the blood flow path, the protein component in the blood enters into the lubricating thin film by diffusion, and is denatured and coagulated by sliding friction heat. The heat-denatured protein does not adhere to the contact surface itself due to high shearing force, but is extruded before and after the contact portion and adheres to a place close to the contact portion. In the case of the mechanical seal of the present invention, the denatured protein is pushed outward by centrifugal force and is mainly discharged to the blood flow path side. The denatured protein discharged to the blood flow path quickly diffuses into the blood by a high-speed blood flow. On the other hand, the protein component slightly precipitated in the area facing the fluid chamber is quickly washed away by a large amount of circulating fluid. Thus, the denatured protein remains near the contact part of the mechanical seal,
Since the contact surface of the mechanical seal is always kept clean without growing, the sealing performance of the mechanical seal is maintained for a long time. Therefore, it is possible to prevent blood adhesion on the rotating shaft for a long period of time.

On the other hand, since the circulating fluid only circulates inside the pump and only flushes out the protein component deposited near the contact end face of the mechanical seal facing the fluid chamber, the amount of circulating fluid flowing out of the gap between the contact faces into the blood flow path is small. Can be extremely small. As a result, the consumption of the circulating fluid is kept low, and there is no need to frequently replenish the circulating fluid.

Further, since a large amount of circulating fluid is circulated and the vicinity of the contact surface of the mechanical seal facing the fluid chamber is washed away, it is possible to suppress a rise in the temperature of the seal contact surface. Not only can red blood cells be destroyed due to local heat generation of blood, but also abnormal wear of the mechanical seal contact surface can be prevented.

In addition, since a large amount of circulating fluid circulates in the air gap of the motor, the circulating fluid acts as cooling water for the motor, thereby suppressing heat generation of the motor and keeping the temperature rise in the drive unit low. The life of the blood pump can be greatly extended.

A shaft sealing mechanism for an artificial heart pump according to one aspect of the present invention includes a rotating shaft (10) integrally formed with all bearing rotors (14a, 14b);
A rotating shaft bearing stator (11a) in which all the bearing stators and a fixing ring (12a) of the mechanical seal (9) are integrally formed, and further, a mechanism for generating a pressure necessary for bringing the opposed contact surfaces into close contact with each other. Having. In this case, it is preferable to use fine ceramics for the material of the fixing ring (12a) and carbon graphite for the material of the rotating ring (13a) opposed thereto.

According to an embodiment of the present invention, the bearing stator of the rotating shaft and the fixing ring of the mechanical seal are integrally formed, and further, the bearing rotor and the rotating shaft are integrally formed. Can be obtained with high accuracy. Further, since the concentricity of all the bearing stators, bearing rotors, and rotating shafts can be obtained with high accuracy, vibration during pump operation can be reduced, and assembly becomes easy.

[0015] Further, the contact surface of the mechanical seal makes it possible to position the rotary shaft in the axial direction, so that a separate thrust bearing is not required. Furthermore, the rotating shaft can be automatically moved in response to the wear of the contact surface of the mechanical seal, thereby always maintaining a good contact surface of the mechanical seal.

Further, in this case, a stable contact surface is maintained for a long period of time by forming the mechanical seal using a material (fine ceramics, carbon graphite) having a property of being worn to fit the corresponding contact surface. It is assumed that.

A shaft seal mechanism of an artificial heart pump according to another embodiment of the present invention includes a bearing rotor (14c) of a rotating shaft (110) integrally formed with a rotating ring (13b) of a mechanical seal (109), and a mechanical seal. (109)
And a bearing stator (11b) integrally formed with the fixing ring (12b), and a mechanism for generating a pressure necessary to bring the opposed contact surfaces into close contact with each other.

That is, the embodiment of the present invention is characterized in that the bearing stator of the rotating shaft and the fixing ring of the mechanical seal are integrally formed, and further, the bearing rotor and the rotating ring of the mechanical seal are integrally formed.
The parallelism of the mechanical seal contact surface can be obtained with high accuracy.

According to another embodiment of the present invention, there is provided a shaft seal mechanism for an artificial heart pump, comprising a mechanical seal (20) having at least one pair of smooth contact surfaces which relatively slide.
9), a mechanism for generating a pressure necessary for bringing the opposing contact surfaces into close contact, a mechanism for transmitting the rotation of the shaft to the contact surface of the mechanical seal, and a vibration or the like caused by the rotation of the shaft. It is characterized in that it has a buffer mechanism for not affecting the gap in the surface.

That is, in the embodiment of the present invention, a seal mechanism is provided so as to prevent a gap from being generated in the contact surface due to vibration or the like caused by rotation of the rotating shaft, thereby preventing seal leakage due to rotational vibration or the like. is there.

According to the present invention, a mechanism for controlling the pressure acting on the contact surface of the mechanical seal and further automatically moving the rotating ring of the mechanical seal in the axial direction of the rotating shaft in accordance with the wear amount of the contact surface. Having. Further, it is desirable to fix the rotor blade boss to the rotating ring of the mechanical seal.

That is, in the embodiment of the present invention, the rotating ring of the mechanical seal automatically moves in the axial direction of the rotating shaft in accordance with the wear amount of the contact surface of the mechanical seal, so that the rotating shaft for a long period of time. It is intended to maintain a stable shaft sealing performance even by the operation.

Further, in the invention according to claim 7,
The other opposing mechanical seal contact surface is fixed together with the blade boss to the tip of the rotating shaft so as to obtain a right angle with the rotating shaft. Therefore, the parallelism between the contact surfaces of the opposing mechanical seals can be obtained with high accuracy.

[0024]

FIG. 1 is an enlarged sectional view of an artificial heart pump body according to an embodiment of the present invention. The pump body will be described in detail below.

In the figure, reference numeral 4 denotes an elongated cylindrical pump base, reference numeral 5 denotes a driving unit for driving a moving blade 16 incorporated therein, and reference numeral 6 denotes a casing having a nozzle portion 7 formed at the tip.

The pump base 4 has a base end connected to the drive unit 5 and a casing 6 fixed to the outer periphery at the tip end. At the lower end of the casing 6, a plurality of suction ports 8 for sucking blood are arranged.

A motor 27 having a rotor 28 is built in the drive unit 5, and a rotating shaft 10 connected to the rotor 28 extends to the tip of the pump base and is connected to the pump blade boss 17. Further, a circulating liquid suction port 20 for sucking and discharging the circulating liquid and a circulating liquid discharge port 26 are provided.

The above-described rotary shaft 10 penetrates the center of the pump base 4. The rotary shaft 10 has at least two bearing rotors 14 a and 14 b having a very shallow spiral groove formed on the surface. It is supported by a bearing composed of the bearing stator 11a (hereinafter, one-way dynamic pressure bearing).
The bearing rotors 14a and 14b are manufactured by integral molding with the rotating shaft 10, and are made of a material having excellent wear resistance such as fine ceramics. Further, the above-described one-way dynamic pressure bearing has a pump function of drawing the surrounding circulating fluid into the sliding surfaces of the bearing rotors 14a and 14b and the bearing stator 11a by rotation of the rotating shaft 10 and sending the fluid in one direction. . Further, the bearing rotors 14a,
A circulating liquid chamber 23 is formed between 14b so as to surround the rotation shaft 10.

A mechanical seal 9 for preventing blood from flowing into the bearing of the rotating shaft 10 is provided between the tip of the pump base 4 and the pump blade boss 17 described above. The mechanical seal 9 is provided at the distal end of the pump base, and includes a fixed ring 12a formed integrally with the bearing stator 11a, and a rotating ring 13a fixed to the rotating shaft 10 together with the pump blade boss 17. Is performed on the contact surface between the cylindrical end surfaces of the fixed ring 12a and the rotating ring 13a. The material used for the mechanical seal may be, for example, carbon graphite, a metal material, ceramics or a ceramics-coated material.
When fine ceramics are used for 4a and 14b, fixing ring 12a integrally formed with bearing stator 11a
It is preferable to use fine ceramics from the viewpoint of wear resistance. Further, the mechanical seal 9
When fine ceramics is used for the fixing ring 12a, it is desirable to use carbon graphite, which has a high self-lubricating effect on the rotating ring 13a and has a property of being worn to fit the corresponding fixing ring. When using fine ceramics for the fixing ring 12a of the mechanical seal and using carbon graphite for the rotating ring 13a, the friction coefficient is about 0.1 to 0.15, which is 0.25 compared to 0.25 when both use fine ceramics. Value.

The pressure required to maintain the contact surface of the mechanical seal 9 is determined by the permanent magnet 29a fixed around the base end of the bearing stator 11a and the motor 2
No. 7 utilizes a repulsive force between itself and a permanent magnet 29b installed in the rotor unit. In this embodiment, the repulsive force of the permanent magnet is used, but it is also possible to use the attractive force.

The bearing rotor 14 at the tip of the pump base
A fluid liquid chamber 24 is formed between a and the mechanical seal 9. Further, a return pipe 2 for circulating the circulating fluid from the fluid chamber 24 to the circulating fluid discharge port 26 of the drive unit 5.
5 are provided. The circulating fluid communicates with the circulating fluid bag 32 from the circulating fluid suction port 20 and the circulating fluid discharge port 26 of the drive unit 5 through the return pipes 30 and 31.

The inside of the casing is integrally formed with a stationary vane 15 for connecting the pump base 4 and the casing 6 and for rectifying the flow of the inflowing blood, and the above-mentioned moving blade boss 17 for applying energy to the inflowing blood. The moving blade 16 includes a stationary blade 18 that collects turning energy generated in the blood by the moving blade 16 as pressure energy. The stationary blade boss 19 is fixed to the adjacent moving blade boss 17, and the stationary blade 18 is fixed to the inner wall of the casing. The number of blades is at least two or more, and they are mutually prime to prevent resonance caused by rotation.

The internal circulating fluid is pumped from the circulating fluid bag 32 by the pumping action of the one-way dynamic pressure bearing.
Through the circulating fluid suction port 20, the motor air gap 21, the sliding surface between the bearing rotor 14b and the bearing stator 11a, the circulating fluid chamber 23, the sliding surface between the bearing rotor 14a and the bearing stator 11a, and Flush the inside of the mechanical seal 9 facing the
And circulates again from the circulating fluid discharge port 26 to the circulating fluid bag 32 via the reflux pipe 31. Further, by providing the filter 33 for removing the denatured protein mixed in the circulating fluid in the circulating fluid bag 32, the clean circulating fluid circulates, so that the safety of the artificial heart can be improved. In addition, the circulating fluid bag 32 is installed inside the body cavity outside the left ventricle or outside the body. In this embodiment, the return pipe is provided separately from the rotary shaft. However, the return pipe may be provided inside the rotary shaft.

By circulating a large amount of circulating fluid whose flow velocity has been increased by the one-way dynamic pressure bearing through the above-described path in the pump, protein components deposited inside the mechanical seal 9 are washed away, and the inside of the mechanical seal 9 is washed away. Is always kept clean. This not only prevents the effect of the precipitated protein component on the contact surface of the mechanical seal 9, but also because a large amount of circulating fluid absorbs the frictional heat of the mechanical seal 9, blood cell destruction due to local heat generation, It prevents abnormal abrasion of the sealing material and enables stable shaft sealing for a long period of time. Further, since the stable sliding surface is maintained, the amount of the circulating fluid flowing into the blood from the mechanical seal contact surface is extremely small.

Further, by circulating a large amount of the circulating fluid through the air gap 21 of the motor 27, the circulating fluid serves to cool the motor 27, and the temperature rise in the drive unit can be kept low. It can be used for a long time and the life of the blood pump can be greatly extended.

FIGS. 2 and 3 show the mechanical seal 9 described above.
Here are the main components. FIG. 2 is a cross-sectional view of a fixing ring 12a of the mechanical seal and a rotating ring 13a of the mechanical seal sharing the function of the mechanical seal with the bearing stator 11a of the rotating shaft 10, and FIG. By integrally molding the bearing stator 11a and the mechanical seal fixing ring 12a, the function of the bearing stator and the mechanical seal fixing ring is shared. Further, the degree of perpendicularity between the axial direction of the rotating shaft and the seal contact surface is absolutely obtained. Further, the bearing rotor 14
If the rotating shaft 10 integrally formed with the shafts 14a and 14b is used, the rotating shaft 10, the bearing rotors 14a and 14b, and the bearing stator 11a can have high concentricity and parallelism. As a result, high rotational accuracy with little vibration can be obtained, and assembly can be easily performed. The rotating ring 1 of a mechanical seal such as carbon graphite, for example, has a property of being worn so as to conform to the corresponding contact surface with the rotating shaft 10 described above.
3a, the fixing ring 12 of the mechanical seal
a and the rotating ring 13a show a high degree of perpendicularity to the rotating shaft 10, and a good contact surface is obtained.

The surface of the bearing rotors 14a and 14b is provided with a shallow spiral groove so that the surrounding fluid can be rotated with the rotation of the bearing rotors 14a and 14b.
It has a pumping function of drawing into the sliding surface of the bearing stator 11a and the bearing stator 11a and sending out in one direction.

The force required to press the contact surface is shown in FIG.
As shown in (1), a pair of permanent magnets 29a and 29b provided inside the motor are used. In FIG. 1, the same poles are opposed to each other, and the repulsive force of the permanent magnet is used. However, it is also possible to use the attractive force. The reaction force generated by the operation of the moving blade 16 also acts as a force for pressing the contact surface. Further, since the repulsive force or attractive force of the permanent magnet and the contact surface of the mechanical seal enable positioning of the rotating shaft in the axial direction, a separate thrust bearing is not required. Further, the rotating shaft 10 can automatically follow the movement in response to the wear of the fixed ring 12a and the rotating ring 13a of the mechanical seal, and as a result, a good contact surface can always be maintained.

FIG. 4 is an enlarged sectional view of another embodiment of the shaft seal mechanism of the artificial heart pump body of the present invention, and FIG. 5 is a detailed view of the shaft seal mechanism of FIG. Since this example is functionally similar to that shown in FIG. 1, the points different from the example of FIG. 1 will be described here.

The mechanical seal 109 is composed of a fixed ring 12b formed integrally with the bearing stator 11b, and a rotating ring 13b formed integrally with the bearing rotor 14c.
This is performed on the contact surface between the cylindrical end surface of the rotating ring 13b and the rotating ring 13b. The material used for the mechanical seal is a combination of fine ceramics-fine ceramics or carbon graphite-fine ceramics.

The force required to bring the contact surfaces of the opposing mechanical seals 109 into close contact is based on the repulsive force of a pair of permanent magnets 29c and 29d installed inside the motor, but an attractive force can also be used.

The circulating fluid flows from the circulating fluid bag 32 through the reflux pipe 30, through the circulating fluid suction port 20, the motor air gap 21, the bypass passage 35, the circulating fluid chamber 23, the bypass passage 36, and through the fluid chamber. The inside of the mechanical seal 109 facing 24 is washed away, circulated through the return pipe 25, circulated from the circulating liquid discharge port 26, through the reflux pipe 31, and back to the circulating liquid bag 32. In this example, an external pump 34 for circulating the circulating fluid is provided between the circulating fluid bag 32 and the circulating fluid suction port 20. In addition, as shown in FIG. 1, the circulating fluid can be circulated only by the pump action of the one-way dynamic pressure bearing, without using the bypass passages 35 and 36 and the external pump 34. Further, by providing the filter 33 for removing the denatured protein mixed in the circulating fluid in the circulating fluid bag 32, the clean circulating fluid circulates, so that the safety of the artificial heart can be improved. In addition, the circulating fluid bag 32, the filter 33, and the external pump 34 are installed inside the body cavity outside the left ventricle or outside the body.

FIG. 6 is an enlarged sectional view of another embodiment of the shaft sealing mechanism of the artificial heart pump body of the present invention. This example is functionally similar to the one shown in FIG. 1 and the circulating fluid is the same as that shown in FIG. I do.

In this embodiment, the moving blade boss 217 to which the moving blade 216 is attached has a degree of freedom in which the moving blade boss 217 can move in the axial direction. However, the rotating blade boss interior 38 and the rotating shaft 210
The permanent magnet 29 is positioned at the tip of the
e and 29f are installed, so that the repulsive force between the permanent magnets causes the rotating ring 13c of the mechanical seal 209 fixed to the bucket boss 217 to be fixed to the fixing ring 1 of the mechanical seal 209 fixed to the tip of the pump base.
2c. In addition, the minute vibration generated during operation is reduced, and the rotating ring 13c of the mechanical seal 209 fixed to the moving blade boss 217 in accordance with the wear of the mechanical seal 209 can follow the axial direction. On the other hand, the positioning of the rotating shaft 210 in the axial direction is performed by providing the flange portion 52 on the bearing rotor 14f of the one-way dynamic pressure bearing provided at the base end portion of the rotating shaft, and providing the permanent magnets 29e, 29
It is determined by bringing the flange portion 52 of the bearing rotor into contact with the end face of the bearing stator 11e by the repulsive force of f.

In this embodiment, the bearing rotors 14e and 14f of the one-way dynamic pressure bearings installed at the leading end and the base end of the rotating shaft 210, the rotating shaft 210, and the bearing stators 11d and 11e are separately provided. Figure 1
Similarly, it is also possible to integrally mold.

FIG. 7 is a sectional view showing details of the mechanical seal 209 of the example shown in FIG.
This is an example in which the contact surface of the mechanical seal 209 is pressed using e and 29f.

In the figure, the function of the fixing ring of the mechanical seal is shared by integrally molding the bearing stator 11d and the fixing ring 12c. Further, the fixing ring 12 of the mechanical seal 209 is formed by integral molding.
At c, the perpendicularity between the axial direction and the seal contact surface is absolutely obtained. Moving blade boss 2 to which moving blade 216 is attached
The rotating ring 13c of the mechanical seal integrally combined with 17 reduces the minute vibration generated during operation by the permanent magnets 29e and 29f having the same pole facing each other so as to obtain a repulsive force. Has a degree of freedom to move in the axial direction correspondingly. However, since the rotating shaft 210 and the rotating ring 13c are connected by the drive pin 39 installed on the rotating shaft 210, the rotating shaft 210 rotates with the shaft without any degree of freedom in the rotating direction.
The shaft sealing action on blood is performed on the contact surface between the fixed ring 12c and the cylindrical end surface of the rotating ring 13c. An O-ring or V-ring made of artificial rubber or the like is used for sealing between the rotor blade boss interior 38 and the internal circulation fluid. The figure shows an example in which an O-ring 40 is used.

FIG. 8 shows an example in which the permanent magnets 29e and 29f used in FIG.
Functionally, it is equivalent to FIG. Further, an elastic body such as a leaf spring or rubber may be used instead of the coil spring.

Although the present invention has been described in the embodiment using the axial flow pump, the same effect can be obtained by using another pump such as a centrifugal pump. Fig. 9 shows an example of a centrifugal pump. FIG. 9 illustrates an example in which the artificial heart main body is installed in a body cavity other than the human heart, unlike the example using the axial flow pump described above. Therefore, cases of diseases such as acute myocardial infarction or acute myocarditis, hypertrophic cardiomyopathy where the left ventricle does not expand, or when the pump nozzle cannot pass through the aortic valve after aortic valve replacement surgery, etc. It can be used even for patients to whom an axial pump cannot be applied.

In the figure, the mechanical seal 309 is
Fixed ring 12 integrally formed with bearing stator 11f
d, and a rotating ring 13d integrally formed with the bearing rotor 14g. The shaft sealing for blood is performed by the above-mentioned fixed ring 12d and the contact surface of the cylindrical end face of the rotating ring 13d. The force required to bring the opposing mechanical seal contact surfaces into close contact utilizes the repulsive force of the permanent magnets 29g and 29h provided inside the motor.

The circulating fluid flows from the circulating fluid bag 32 through the reflux pipe 30, through the circulating fluid suction port 20, the air gap 21 of the motor, and the bypass passage 35, and passes through the inside of the mechanical seal 309 facing the fluid chamber 24. Rinse, pass through the return pipe 25, and return from the circulating fluid discharge port 26 to the reflux pipe 31.
And circulates again to the circulating liquid bag 32.

In this embodiment, an external pump 34 for circulating the circulating fluid is provided between the circulating fluid bag 32 and the circulating fluid suction port 20. Further, it is also possible to circulate the circulating fluid only by the pump action of the one-way dynamic pressure bearing, as shown in FIG. 1, without using the bypass passage 35 and the external pump 34. Further, by providing the filter 33 for removing the denatured protein mixed in the circulating fluid in the circulating fluid bag 32, the clean circulating fluid circulates, so that the safety of the artificial heart can be improved. In addition, the circulating fluid bag 32, the filter 33, and the external pump 34 are installed inside the body cavity outside the left ventricle or outside the body.

[0053]

As described above, the present invention has the following effects.

According to the first aspect of the present invention, a stable sealing function can be realized by the mechanical seal, the fluid for rinsing the inside of the mechanical seal, and the mechanism for circulating the circulating fluid. As a result, it is possible to prevent blood from coagulating on the rotation axis of the pump, and it is possible to use the heart pump safely for a long period of time.

Further, the consumption of the circulating fluid is stable at a low flow rate. Furthermore, since the shape of the flow path through which blood flows is optimally obtained in a fluidological manner, a pump with less stagnation and destruction of blood can be realized.

According to the second aspect of the present invention, the squareness between the rotating shaft and the contact surface of the mechanical seal can be obtained with high accuracy, and therefore, stable sealing performance can be maintained for a long period of time. Further, since the concentricity of the bearing rotor of the rotating shaft can be easily obtained, the assembly can be easily performed.

Further, since the contact surface of the mechanical seal enables positioning of the rotating shaft in the axial direction, a separate thrust bearing is not required. Further, the rotating shaft can automatically move in accordance with the wear of the contact end face of the mechanical seal, so that a good contact face of the mechanical seal can be always maintained.

According to the third aspect of the present invention, the mechanical seal is formed by using a material having a property of being worn to fit the corresponding contact surface, thereby maintaining a stable contact surface for a long time. Becomes possible.

According to the fourth aspect of the present invention, since the parallelism between the opposing mechanical seal contact surfaces can be obtained with high accuracy, stable sealing performance can be maintained for a long period of time.

According to the fifth aspect of the present invention, by providing a buffer mechanism for preventing a gap from being generated in the contact surface due to vibration or the like caused by rotation of the rotating shaft, seal leakage due to rotational vibration or the like is prevented. Can be.

According to the sixth aspect of the present invention, the rotation of the rotary shaft in the thrust direction is automatically performed in accordance with the amount of wear of the contact end face of the mechanical seal, so that the shaft seal can be stably operated even over a long period of time. Performance can be maintained.

According to the seventh aspect of the invention, the parallelism between the contact surfaces of the mechanical seals can be obtained with high accuracy by integrating the rotor blade boss and the rotating ring of the mechanical seal.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of an artificial heart pump body according to an embodiment of the present invention.

FIG. 2 is a detailed sectional view of the mechanical seal 9 of FIG.

FIG. 3 is a detailed view of a rotating shaft 10 of FIG.

FIG. 4 is an enlarged sectional view of an artificial heart pump body according to another embodiment of the present invention.

FIG. 5 is a detailed sectional view of the mechanical seal 109 of FIG.

FIG. 6 is an enlarged sectional view of an artificial heart pump body according to another embodiment of the present invention.

FIG. 7 is a detailed sectional view of the mechanical seal 209 of FIG.

FIG. 8 is a detailed cross-sectional view of the mechanical seal 209 of FIG.

FIG. 9 is an enlarged sectional view of an artificial heart pump body according to another embodiment of the present invention.

FIG. 10 is an explanatory view showing a state in which a conventional artificial heart main body is attached to a human heart.

[Explanation of symbols]

A: heart B: left ventricle C: apex D: aortic valve E: ascending aorta 1 ... artificial heart 2 ... apex ring 3 ... artificial heart body 4 ... Pump base 5 ... Driver 6 ... Casing 7 ... Nozzle 8 ... Suction port 9,109,209,309 ... Mechanical seal 10,110,210,310 ...・ Rotating shafts 11a, 11b, 11c, 11d, 11e, 11f
· Bearing stators 12a, 12b, 12c, 12d ... fixed rings 13a, 13b, 13c, 13d ... rotating rings 14a, 14b, 14c, 14d, 14e, 14f, 1
4g: Bearing rotor 15: Front stationary blade 16, 216: Moving blade 17, 217: Moving blade boss 18: Static blade 19: Static blade boss 20: Circulating fluid Suction port 21 Air gap 23 Circulating fluid chamber 24 Fluid fluid chamber 25 Return pipe 26 Circulating fluid discharge port 27 Motor 28 Rotor 29a, 29b 29c, 29d, 29e, 29f, 2
9g, 29h: Permanent magnets 30, 31, Reflux tube 32: Circulating fluid bag 33: Filter 34: External pump 35, 36 ... Bypass flow path 38: Blade boss Inside 39 Drive pin 40 O-ring 41 Coil spring 50 Sealed liquid bag 51 Flow tube 52 Collar

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-7-178165 (JP, A) JP-A-6-181983 (JP, A) JP-T-61-500058 (JP, A) (58) Investigation Field (Int.Cl. ⁶ , DB name) A61M 1/12

Claims (7)

(57) [Claims] 1. An artificial heart pump for use in a human body, wherein the pump is provided via a cylindrical pump base (4) and a rotating shaft (10) of a motor (27) connected to a base end of the pump base. Base (4) Rotor blade (1) of pump installed at tip
6) a drive unit (5) for driving the pump base; and a casing (6) formed at the distal end of the pump base, and a bearing rotor ( 14a, 14b) and a bearing stator (11a), and the bearing rotor (14) extends from the tip of the pump base (4).
a, 14b) and at least one set of end face rotary contacts having radially smooth contact faces of said rotary shaft for preventing blood from penetrating into the sliding faces of the bearing stator (11a). Type seal part (hereinafter referred to as mechanical seal) (9, 109, 2
09, 309) and the mechanical seals (9, 10
9,209,309) and the flow liquid chamber formed between the bearing rotor (14a) and (24), said mechanical seal (9, 109 facing the flow fluid chamber (24),
Circulation for circulating the circulating fluid to wash away 209, 309)
And a mechanism for sealing an artificial heart pump. 2. The mechanical seal according to claim 1, wherein the mechanical seal comprises a rotating shaft and a bearing stator.
1a) and a rotating ring (13a) fixed to a rotating shaft (10) integrally formed with the bearing rotors (14a, 14b). (12a) and the rotating ring (13a)
A seal mechanism for an artificial heart pump, characterized by having a mechanism for generating a pressure necessary to bring the opposing contact surfaces into close contact with each other. 3. The rotary shaft (10) according to claim 2, wherein:
A seal mechanism for an artificial heart pump, wherein fine ceramics is used as a material of a fixing ring (12a) of a mechanical seal having a function of a bearing stator (11a), and carbon graphite is used as a material of an opposing rotating ring (13a). 4. The bearing according to claim 1, wherein said mechanical seal comprises a fixed ring integrally formed with a bearing stator and a bearing rotor.
c) and a rotating ring (13b) integrally formed, wherein the fixed ring (12b) and the rotating ring (13b)
A shaft sealing mechanism for an artificial heart pump, characterized by having a mechanism for generating a pressure necessary for bringing a contact surface opposed to the shaft into close contact. 5. A mechanism according to claim 1, wherein a mechanism for generating a pressure necessary for bringing the opposing contact surfaces of said mechanical seal (209) into close contact with each other, and a mechanism for transmitting rotation of a rotating shaft (210) to said contact surface. And a buffer mechanism for preventing a gap from being generated in the contact surface due to vibration or the like caused by rotation of the rotation shaft (210). 6. The mechanical seal according to claim 1, wherein a pressure acting on a contact surface of the mechanical seal is controlled, and further, the mechanical seal is controlled in accordance with a wear amount of the contact surface of the mechanical seal. Rotating ring (1
3a, 13b, 13c, 13d) are the rotating shafts (10,
(110, 210, 310) in the axial direction automatically. 7. The blade boss (17, 2) according to claim 1,
17) A sealing mechanism for an artificial heart pump, wherein a rotating ring (13a, 13c) of the mechanical seal (9, 209) is fixed to the mechanical seal.